Foldable mobile telephones widely used in recent years generally have a mechanism joining an upper case and lower case at a hinge part allowing the foldable mobile telephones to open and close. Furthermore, many terminals in lately released mobile telephones place importance on design, incorporate antennas and pursue thinness. (for example, refer to Patent Document 1.)
In case a user makes a call using such a mobile telephone, the state where the user holds the mobile telephone with a hand and places it close to the ear (hereinafter referred to as “calling state”) is common. In case the user performs communication such as e-mail or video phone, the state where the user operates the mobile telephone by holding it in front of the chest with a hand (hereinafter referred to as “operating state”) is common. In these various usage states, to maintain good communication quality, there is a technology of antenna switching diversity that provides a plurality of antennas at the comparatively distant parts on a mobile telephone and switches antennas in accordance with the usage states (for example, refer to Patent Document 2).
In antenna switching diversity system, antenna becomes temporary unconnected (open) at the moment antennas switch during communication, and antenna gain fluctuates substantially before and after switching. In TDMA system, switching diversity operation is implemented in the guard time other than the slot which is necessary for communication, and therefore the momentary disconnection and gain fluctuation of an antenna are not a problem.
Patent Document 1: Laid-Open Japanese Patent Publication No.2001-156898
Patent Document 2: Laid-Open Japanese Patent Publication No.2002-64314